Australian Study Association Inc. – Bird in the Hand (Second Edition), published on www.absa.asn.au

Torresian orru Species No.: 692 Band size: 10

Morphometrics: The only subspecies in is C.u. cecilae and its measurements are provided below: Adult Male Adult Female Wing: 315 – 382 mm 320 – 363 mm Tail: 179 – 214 mm 176 – 221 mm Bill (tip to skull): 57.5 – 66.1 mm 53.5 – 63.6 mm Weight: 430 – 670 g 430 – 650 g

Ageing: Adult (3+) 2nd Immatures (2) 1st Immature (1) & Juvenile Bill: black; grey- black; grey-black: initially with pinkish base to lower mandible; Gape: black; blackish-pink; pink or reddish; Palate: black; blackish-pink; pink or reddish; Interramal skin: black; blackish-pink; pink; Iris: white, with pale blue hazel; blue-grey changing to brown by inner ring; three months of age; Remiges & rectrices: blackish with glossy as for adult; blackish-brown; greenish sheen grading to bluish-purple at tips;

Juveniles undergo a partial moult to first immature plumage soon after fledging; First Immatures retain all or most juvenile remiges, greater primary coverts, alula and rectrices. Note that outer primaries and tail feathers differ in shape from adults – see illustration below; First immatures commence moult to second immature plumage, which is indistinguishable from adult plumage, at approximately one year old; Second immatures, identified by subtle differences in bare parts, attain full adult colouring in a complete moult commencing at the end of their second year. Thus adults aged (3+);

Sexing: There is no plumage dimorphism, though adult males average larger than adult females; Incubation is by the female only.

Similar species: Other Australian corvids – see illustrations of hackles above.

References: HANZAB 7; Drawings: N. Day in HANZAB 7 - © BirdLife Australia Compiled by Australian Bird Study Association Inc. and reproduced with permission of BirdLife Australia